Conventional wide base, low aspect ratio truck tires have replaced two small base tires, so-called dual mounted tires. These conventional tires have typically been used on trailers because of their high load bearing ability. These wide base tires have also been used in the steering position of trucks because of typically higher mileage capabilities.
Tires in a drive position may also bear part of a trailer load and must have an increased load capacity. Wide base, low aspect ratio drive tires are often exposed to harsh service conditions. Conventional constructions have shown crown area durability problems. Also, pressure distribution through the footprints of these conventional wide base, low aspect ratio constructions has lacked acceptable uniformity.
One conventional pneumatic tire has been used on heavy vehicles. Radially outwards of the belt layers is at least one layer of metallic cords parallel to one another and substantially parallel to a circumferential direction of the tire. The metallic cords have an ultimate elongation between 4 and 8% and are formed by a single helically wound cord.
One conventional passenger tire has a wound ribbon reinforced with cords helically in at least two layers on top of belt plies. The ribbon has a width comprised between 15 and 45 mm. The reinforcing cords are nylon and have a lateral density of about 30 ends per inch (EPI).
Another conventional pneumatic tire has a crown reinforcing structure for pneumatic tires including a helically wound ribbon reinforced with steel cords. The ribbon has a width comprised between 5 and 50 mm and is directly wound on the carcass ply.
Still another conventional pneumatic tire has a reinforcing layer of straight metallic cords parallel to one another and substantially parallel to a circumferential direction of the tire. Such tire purports to have diminished running noise.
Yet another conventional pneumatic tire has a reinforcing layer of wavy or zigzag metallic cords parallel to one another and substantially parallel to a circumferential direction of the tire. Such tire purports to improve cornering characteristics.